Magnetic recording disc cartridge with disc cleaning means

Abstract

A magnetic recording disc cartridge so called a floppy disc comprising a cover jacket member enclosing a magnetic recording disc with a cleaning sheet disposed between the inside face of the cover jacket member and the magnetic recording disc, including thermally bonding portions for bonding the sheet member and the cleaning sheet, in which the bonding portions are a plurality of dots formed around the peripheral portion of a central window along a plurality of lines radially extending from the peripheral edge of the central window for a predetermined distance.

What is claimed is: 
     
       1. A magnetic recording disc cartridge which comprises a magnetic recording disc, a cover jacket means having a chamber defined by a pair of opposed sheet members for rotatable accommodation of the magnetic recording disc, with the sheet members being provided with central windows on each of the sheet members for receiving a drive shaft of a recording/reproducing apparatus, at least one elongated head window for receiving a recording/reproducing head of said apparatus and at least one small index window defined at the peripheral portion of the central window on at least one of the sheet members, at least one cleaning sheet disposed between at least one of the sheet members and the corresponding surface of the magnetic recording disc, said cleaning sheet being made of a non-woven cloth and having central windows, head windows and index windows each of which is formed corresponding to the windows defined on the sheet members, and thermally bonding portions for bonding the sheet member and the cleaning sheet, said bonding portions being a plurality of dots formed around the peripheral portion of the central window along a plurality of lines radially extending from the peripheral edge of the central window for a predetermined distance. 
     
     
       2. A magnetic recording disc cartridge as claimed in claim 1, wherein said cover jacket means further comprises a plurality of thermally bonding portions located on the trailing side of the index window with respect to the direction of rotation of the disc on the cleaning sheet. 
     
     
       3. A magnetic recording disc cartridge as claimed in claim 1, wherein said thermally bonding portions around the central window are formed with the density of the bonding spots located on the leading side of the central window with respect to a direction of the insertion of the recording disc into the jacket means being higher than the density of the bonding spots located on the trailing side of the central window. 
     
     
       4. A magnetic recording disc cartridge as claimed in claim 1, wherein said high density bonding spots located on the leading side are disposed in an angular range of 20° to 120° with respect to the center of the central window. 
     
     
       5. A magnetic recording disc cartridge as claimed in claim 4, wherein said angular range is 30° to 60°. 
     
     
       6. A magnetic recording disc cartridge as claimed in claim 1, 2, 3, 4 or 5, wherein said jacket means further comprises a plurality of parallel lines of bonding portions extending linearly for bonding the cleaning sheet and the sheet members. 
     
     
       7. A magnetic recording disc cartridge as claimed in claim 1, 2, 3, 4 or 5, wherein each of the innermost bonding spots with respect to the central window is formed at the peripheral edge thereof.